Microsoft Corp., Intel Corp., Google Inc. and other tech companies called on the U.S. Federal Communications Commission to move forward with a proceeding to make unused television spectrum available for wireless networking technologies.

Members of the White Spaces Coalition, also including Dell Inc. and Hewlett-Packard Co., on Tuesday said they intend to keep the pressure on the FCC to meet its deadline of issuing final rules on the use of unlicensed wireless devices in spectrum white spaces, which are empty TV channels available in every city.

"There are unused TV channels which essentially lie fallow," said Scott Blake Harris, an attorney representing the White Spaces Coalition. "This is ... spectrum that can be used to provide important services to the American public."

The coalition's news briefing on white spaces came a week after two U.S. representatives introduced the Wireless Innovation Act, which would require the FCC to quickly issue a final order in its white spaces proceeding. Two bills introduced in the U.S. Senate in January require the same thing.

Under the FCC timeline, devices using the white spaces could be available for sale in February 2009, after broadcasters are required to move off channels above channel 51 and switch from analog to digital broadcasts.

Television broadcasters question whether dozens of new wireless devices in prime TV spectrum will interfere with signals. The National Association of Broadcasters and the Association for Maximum Service Television in comments filed with the FCC earlier this month said broadcasters, wireless microphone makers and public safety officials have "identified serious interference concerns" with unlicensed devices operating between TV channels 2 and 51.

The two groups said unlicensed advocates "provide little or no technical data to support their positions," while broadcasters have provided measured test data. "All of the measurement data submitted in the records support the [broadcasters'] technical positions," the groups wrote in their FCC filing.

The broadcasters also expressed concern that the white spaces proceeding could interfere with their move to digital TV, required by the U.S. Congress in a law passed last year. Broadcasters are required to abandon upper channels, with the spectrum going to public safety agencies and to commercial bidders, and move to lower channels where there now is white space.

But members of the White Spaces Coalition said Tuesday they have technology that can scan for TV channels in use and move to other spectrum. Two weeks ago, Microsoft submitted a radio receiver and transmitter that recognizes TV signals to the FCC, they said.

The low-channel TV spectrum has great possibilities for new wireless applications, members of the White Spaces Coalition said. That part of the spectrum would allow for longer-distance wireless signals than Wi-Fi, and the signals would better go through buildings, trees and other obstacles.

The spectrum would be ideal for rural broadband services, where providers aren't likely to have high-speed wires, as well as in-home networking that would allow devices to share bandwidth intensive content, coalition members said.

White space devices could sell as well as Wi-Fi and Bluetooth devices have, said Marjorie Dickman, senior attorney for government affairs at Intel. "We see the white spaces as a prime opportunity for innovative wireless solutions for consumers. Intel ... is exploring a number of low-power, in-home white space applications."

This story was corrected on March 27, 2007